A composite driving belt as mentioned above is described in patent specification EP No. 80200035.6. The composite driving belt described therein has transverse elements which have been bevelled radially inwards below the neutral line of the driving belt on at least one of their principal faces in order to permit bending of the driving belt, in such a manner that the transverse elements are in contact with one another on the tilting line where the bevelled zone changes into the parallel part of the principal face, whilst the transverse elements are provided with means of engagement in the form of at least one embossment on a principal (flat) face and a substantially corresponding recess on the other principal face.
For an effective usage of such a metallic belt linking two (adjustable) V-shaped metal pulleys, it is imperative that an oil film is present between the elements of the belt and the walls of the pulleys. This is important for several reasons, such as a controlled coefficient of friction between the elements and the pulleys, an increase in abrasion resistance and hence in useful life, prevention of metal-metal contact and hence of scuffing in case of overloading and the like.